There is no kind of book like those geared towards children, but with incredible literary potential. Here is a list of those books that I enjoyed when I was younger, but can still pick up and have a good time with as I am (close to) adult age.
1) The Little Prince by Antoine De-Saint Exupery- This nice little book is the journey of two people, a man who is stranded in a desert, and a boy prince from another planet. The two people meet and the man gets told the Prince's tale of affection toward a flower, and fear of it dying. The prince travels to random planets before finding Earth, and in the proccess he meets a number of interesting people. The book is written in an affectionate way, like The Prince was someone close to the author.
2) The Chronicles of Narnia by CS Lewis- This is actually seven books in a series. They are sold seperately or in one large volume. Some of the volumes I have read close to ten times, others only four or so times. They're a fantastic journey into a fantasy land called "Narnia" where animals talk, dragons exist, and a lion is King. Probably the best place to start is "The Lion, The Witch, and the Wardrobe" which gives the best introduction to the land and main characters.
3) The Phantom Tollbooth by Norton Juster- Yet another fantasy, only this one has more of an educational slant. Milo, a ten year old boy, has a lazy, boring life. He sits around and does nothing, wishing he was somewhere else. He doesn't think or act if he can help it. Then his life is turned upside-down when he discovers a key into a strange world. There he is forced to start thinking. He learns how to use words and numbers and saves to princesses while meeting all sorts of queer people and facing his own fears.